Stump for watchmaker&#39;s staking-tools.



M. A. LESSER.

STUMP FOR WATCHMAKERS' STAKING TOOLS.

APPLICATION FILED NOV. 22. 1915.

' 1,236,849. Patented Aug. 14,1917.

MEYER A. LESSER, OF SAN FRANCISCO, CALIFORNIA.

STUMP FOR WATCI-IMAKERS STAKING-TOOLS.

Specification of Letters Patent.

Patented Aug. 14, 1917.

Application filed November 22, 1915. Serial No. 62,822. i

To all whom it may concern:

Be it known that I, MEYER A. LESSER, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Stumps for IVatchmakers Staking-Tools, of which the following is a specification.

This invention relates to tools for separating the parts of watches, and has for its object to provide a convenient tool of this character, which may be used to remove from the staff of a balance-wheel the disk known as the roller table.

The roller table is a small disk of steel or of some non-magnetic material which carries the roller jewel and is forced upon the staff of the balance-wheel by what is termed a drive fit. In repairing watches it is frequently necessary to remove the roller table from the staff. This is done by supporting the table and driving the staff out by means of a punch. During this operation the roller table is very liable to become bent or distorted, especially when it is made of non-magnetic material. The edges are also liable to be marred, necessitating the repolishing of the table surface and the removal of the resulting bur.

The main purpose of my invention is to facilitate the removal of the roller table from the staff and preventing any injury thereto by providing a proper supporting tool having adjustable jaws for holding the table and permitting the use of an independent punch of the proper size to fit the staff.

Referring to the drawings, Figure 1 is a perspective view of a staking tool and showing the manner of using my improved stump tool therewith; Fig. 2 is a side elevation of a stump embodying my invention and illustrating the manner of removing the stafi from a roller table Figs. 3 and 4 are respectively, top plan and vertical sections of the same and Fig. 5 is a partial end view; and Figs. 6 and 7 are detail views.

As previously stated, great difficulty has been experienced by watchmakers in removing the roller table from the staff without injury to the roller especially when the latter is made of some non-magnetic composition. It is also preferable to be able to select the proper one of a set of punches which is suited to the size of the particular stall to be removed to thereby avoid any damage to the pivots. I have therefore provided a stump which may be used with an ordinary staking tool 2, illustrated in Fig. 1, in which any one of a set of punches 3, may be used.

In Fig. 2, I have shown a stump embodying my invention, having a base 5, provided with a depending post 6, adapted to fit in any one of the series of holes 7, in the revolving platen 8, of the staking tool. The clamping-head comprises two jaws 9, 9, which are provided with dove-tail slides 10, and with threaded apertures engaging a right and left hand screw 12 which may be turned by a wrench or key 14 applied to the squared end to cause the jaws to approach or recede. In order to prevent the jaw members from sliding in the transverse groove in the base and to maintain them rigidly in any adjusted position, I provide a plunger 15, fitting a. recess 16, in the post 6, having a reduced squared end 15 the sides of which bear respectively against the opposite sides of a groove cut-away or turned in the center of the screw 12 and separating the oppositely threaded portions. The plunger is held up against this grooved part by a spring 17.

To insure a solid foundation to receive the impact resulting from the blows given to the punch, I extend the parts 9 of-the jaw members and preferably make them arcuate as shown to give them an increased bearing surface upon the base 5; and to further insure that the impact shall be transmitted directly to the base and not to the screw, I proportion the dove-tail slides or shanks 10, to be slightly above the bottom of the groove leaving a space therebetween.

In Figs. 2 and 3, I have shown a balancewheel 20, supported upon the clamping-head of my stump in position to remove the stem 21, from the roller table 25, the jaw 9, being provided with a slot 26, to receive the lower projecting end of the ewel 27 It will be observed that it is necessary in the first place to separate the jaws a distance equal to the width of the spoke or bridge piece 28, of the balance-wheel and to also provide sufficient room below the top surface and within the inclosure of the jaws to accommodate the spoke when the roller table is in proper position. If, however, the jaws are permanently separated at a distance apart sufficient to permit the passage of the spoke, the

roller table willnot be adequately supported to withstand the blows of the punch in driving out the staff.

To overcome the disadvantages above referred to, I provide anvil-like jaws having a large flat bearing surface which are adjustable toward and from each other while maintaining their top bearing surfaces always level or in the same horizontal plane, and with their inner vertical walls hollowed out, preferably in arcuate shape, as illustrated, to thereby permit the adjacent edges to be brought close to the staff and overhanging the inclosed space between the jaws: which affords ample room for the spoke of the balance-wheel. The arcuate inner walls of the jaws not only provide ample room to receive the spoke, permitting it to pass beneath the overhanging jaws, but the arched form of the metal provides a veryv rigid support for said overhanging portion of the jaws.

The advantages due to the several features of my invention above described will be especially appreciated by watchmakers and those familiar with watch repairing. The manner of mounting and actuating the jaws provides for fine adjustments to accommodate any shape or size of balance-wheel and an exceedingly rigidbase to receive the impact of the blows imparted by the punch; while the form of the jaws afiords a maximum bearing surface which assuresa complete support for the roller table to prevent bending or other injury thereto. My improved stump is especially advantageous when it is desired to remove a: double roller balance staff because the end of the staff projects only a short distance above the roller table and requires a special punch to drive the staff from the roller. The change to a special punch can be readily'made with my stump which permits the use of any size punch.

I claim 2- 1. A tool for supporting the balance wheel of a watch while the staff is being removed from the roller table, comprising a base block, jaws slidably mounted thereon, means for causing said jaws'to approach or recede while maintaining their top bearing surfaces in the same plane, said jaws having arcuate inner vertical walls, to provide meeting edges overhanging a space inclosed by said inner walls, and means preventing lateral sliding of the jaws upon the base block.

2. A toolfor supporting the balance wheel of a watch while the staif is being removed from the roller table, comprising a base block having a transverse groove, jaw members having depending shanks slidable in said groove but spaced from the bottom thereof, said members having extended portions bearing upon said base block, and means for adjusting said jaws toward and from each other.

8. A tool for supporting the balance wheel of a watch while the staff is being removed from the roller table, comprising a base block, jaws slidably mounted thereon, said jaws having inner walls sloping downwardly and outwardly from the top edge to thereby provide an inclosed space between the jaws, and means for causing the jaws to approach or recede while maintaining their top bearing surfaces in the same horizontal plane.

In testimony whereof I affix my signature in presence of two witnesses.

MEYER A. LESSER.

Witnesses:

CURTIs HILLYER, GRACE CARTER.

dopiusot thisipatent-may be obtained-for five cents each, by addressing the "Commissioner of Patents, Washington, D. G. 

